如何使用Python AST模块获取赋值节点的所有目标和值？

import ast

code = """
x = 5
y = x + 2
z = "hello"
"""

tree = ast.parse(code)

# 遍历语法树
for node in ast.walk(tree):
    # 判断节点类型是否为赋值节点
    if isinstance(node, ast.Assign):
        targets = []
        values = []
        
        # 获取赋值节点的目标和值
        for target in node.targets:
            # 获取目标节点的名称
            target_name = target.id
            targets.append(target_name)
        
        value = node.value
        
        # 获取值节点的值
        if isinstance(value, ast.Str):
            values.append(value.s)
        elif isinstance(value, ast.Num):
            values.append(value.n)
        
        print("目标:", targets)
        print("值:", values)
        print("-------------------------")

目标: ['x']
值: [5]
-------------------------
目标: ['y']
值: []
-------------------------
目标: ['z']
值: ['hello']
-------------------------